{

  const pdom = document.querySelector(".product");
  const productListDom = document.querySelector(".product-list");

  for(let i=0;i<20;i++){
     productListDom.insertAdjacentHTML("beforeEnd", pdom.outerHTML);
  }

  // 一级菜单
  const adom = document.querySelector("nav > a");
  const uldom = document.querySelector("nav > ul");
  adom.addEventListener("click", function(event) {
       uldom.classList.toggle("open");
  });

  // 二级菜单
  const second = document.querySelector(".menu-item-click");
  const secondUl = document.querySelector(".second-menu-item");
  second.addEventListener("click", function (event) {
    secondUl.classList.toggle("open");
  });

  // 三级菜单
  const third = document.querySelector(".third-menu-item-click");
  const thirdUl = document.querySelector(".third-menu-item");
  third.addEventListener("click", function (event) {
    thirdUl.classList.toggle("open");
  });

}
